Salicylic acid ester and amide photographic coupler compounds



SALICYLIC ACID ESTER AND AMIDE PHOTO- GRAPHIC COUPLER COMPOUNDS N Drawing. Application October 12, 1953,

' Serial No. 385,704

2 Claims. (Cl. 95-6) This invention relates to the use of salicylic acid ester and salicylic acid amide coupler compounds in color photography.

Salicylic acid and certain substituted salicylic acids such as p-amino salicylic acid have been mentioned as useful as coupler compounds in the color development process of color photography. However, there is little use for salicylic acid in color development processes where it is desired to obtain non-dilfusing dye images and dye images having good stability inasmuch as salicylic acid couples very poorly with the oxidation products of color developing agents, it produces very unstable dyes and indeed the dye images therefrom readily diffuse from the hydrophilic organic colloid emulsion layers. In fact, dye images obtained from salicylic acid in the, color development process are so soluble that they may be readily washed from an emulsion layer during the processing steps customarily following the color development step. 1

We have obtained some improvement in coupling ability by utilizing salicylic acid amides as couplers in color development processes; however, as in the case of salicylic acid the resulting dyes have poor stability.

We have now discovered that salicylic acid amides (including the salicylic acid anilides) and salicylic acid esters, having an electron-donating substituent in the nuclear position para to the amide or ester group, have greatly improved coupling rates in color development processes and yield much more stable dye images compared to either salicylic acid or unsubstituted salicylic acid amides.

The salicylic acid derivatives, having the indicated electron-donating group, with which our invention is concerned and which can be used in the color development of exposed silver halide emulsion layers therefore have the following general formulas:

. OH I O O 0 R1 and O O N HR:

wherein R represents an alkoxyl group e. g. methoxyl or an electron-donating substitutent such as an amino group, an acylamido group, e. g. acetamido, benzamido, stearamido, etc., R1 represents an alkyl group of the order of l-20 or more carbon atoms, or a monocyclic aryl group, e. g., methyl, ethyl, n-propyl, n-butyl, stearyl, phenyl, o-tolyl, m-chlorophenyl, etc., and R2 represents a hydrogen atom, alkyl or aryl groups as indicated above. In

United. States Patent 0 2,728,660 Patented Dec. 27, 1955 addition, the salicyl nuclei of the couplers may be further substituted with, for example, alkyl groups such as methyl to change the color of the dye obtained from the couplers or other groups such as solubilizing groups which do not impair the electron-donating function of the substitutent in the para position.

The following compounds have one of the above general formulas and are representative of the coupling compounds contemplated by our invention. The compounds all produce cyan dye images when used in color development processes.

Coupler No. 1 was prepared according to Drain et al. (J. C. S. 1949, 1498-1503).

Coupler No. 2 was prepared from 2.59 parts of 2-carbophenoxy-S-nitrophenol (BeiL, 10, 118) heated with 1.12 parts of aniline at 180-200 C. for 1 hour and the phenol formed was distilled out. The product, 2-phenylcarbamyl-S-nitrophe'nol II, was recrystallized from volumes of alcohol. Two parts of II in 50 volumes of alcohol were catalytically reduced, the solution filtered, evaporated to a syrup and allowed to crystallize to yield the product, coupler No. 2. The simple amide and lower alkyl amides corresponding to coupler No. 2 are prepared similarly using ammonia or the required alkyl amine in place of aniline.

Coupler No. 3 was prepared by the same method as that used for preparing coupler No. 2 except substituting an equivalent amount of octadecyl amine for aniline.

Coupler No. 4 was prepared as follows:

To a solution of 2 parts of 5-amino-2 carbethoxyphenol and 2 parts of sodium acetate in 40 volumes of glacial acetic acid was added one part of acetyl chloride in 20 volumes of glacial acetic acid. The temperature rose from 28-34 C., and a solid separated in a short time. This mixture was left standing at room temperature overnight, after which time it was diluted with 200 volumes of water. The product was collected and dried.

Coupler No. 5 was prepared as was coupler No. 4, benzoyl chloride being used in place of acetyl chloride.

Coupler No. 6 was prepared as follows:

In 10 volumes of glacial acetic acid was placed 1 part sodium acetate, 1.38 parts of coupler No. 3 and .475 part of acetyl chloride was then added dropwise. The mixture was heated momentarily to 40 C. and after standing overnight, poured into 50 volumes of water. The crystals were collected and drie Coupler No. 7 was prepared as follows:

In 10 volumes of glacial acetic acid were placed .3 part of sodium acetate, 1 part of coupler No. 3 and then .196 part of acetyl chloride was added dropwise and stirred overnight. The mixture was poured into 25 volumes of water, crude product collected and crystallized from alcohol. The crystals were collected and dried.

Coupler No. 8 was prepared as follows:

In 10 volumes of acetic acid were placed 1 part of sodium acetate and 1.38 parts of coupler No. 2 with 1.83 parts of stearoyl chloride, and allowed to stir until the 7 stand overnight.

mixture set. After standing overnight, the solid was mixed with 30 volumes of water, filtered, washed, and crystals dried.

4-ethoxysalicylic acid was prepared according to Perkin (J. C. S. 67, 995) or Gregor (Monatsh. 16, 891).

Coupler No. 9 was prepared according to Perkin (J. C. S. 67, 995).

Coupler No. 10 was prepared as follows:

In a suitable flask were placed 48 parts of 4-ethoxysalicylic acid and 32 parts of phenol. The solid Was mixed with 26.4 g. of phosphorous oxychloride, heated on a steam bath hours with stirring, and allowed to The solid was washed with water, crystallized from 400 volumes of alcohol. The crystals were collected and dried.

Coupler No. 11 was prepared as follows:

In a suitable flask were placed 5.18 parts of coupler No. and 2.32 parts of aniline, and the mixture heated at l80-200 C. for 3 hours. The solid was crystallized from 110 volumes of alcohol, crystals collected and dried.

Coupler No. 12 was prepared inthe manner of coupler No. 11, octadecylamine being used'in place of aniline.

It will be apparent that couplers such as couplers No. 3, 7, 8 and 12 containing the stearamido group, octadecyl group, or other high molecular weight groups are particularly non diffusing in 'hydrophilic colloid silver halide emulsion layers and are therefore particularly adapted to dispersion in emulsion layers by means of crystalloidal materials alone or together with other coupler compounds such as known colored couplers used for color correction purposes,

The crystalloidal materials which are used for dispersing the above coupler compounds in hydrophilic photographic emulsion layers are water-insoluble, organic, crystalloidal materials having boiling points above about 175 C. The crystalloidal materials have a high solvent action for the color formers as well as for the dye images formed therefrom. Examples of the crystalloidal materials useful in our invention are N,N-diethylcapramide, di-n-butylphthalate, N-n-amylphthalimide, tetrahydrofurfuryl benzoate, triphenyl phosphate, n-butyl sulfone, ethyl-N,N-di-n-butylcarbamate, ethyl-N-phenylcarbamate, tetrahydrofurfuryl succinate, ethyl benzyl malonate, methyl phthalate n-butyl phthalate, n-amyl phthalate, 8- methoxyethyl phthalate, .B-ethoxyethyl phthalate, p-butoxyethyl phthalate, butyl o-methoxy benzoate, n-hexyl benzoate, benzophenone, p-sec-amylbenzophenone, tricresyl phosphate, diphenyl mono-p-tert. butyl phenyl phosphate, monophenyl di-o-chlorophenyl phosphate, trio-phenylphenyl phosphate, p-toluenesulfonyl methyl-ot toluidine, p-toluenesulfonyl dimethylamide, p,p'-di-namylbenzenesulfonamide, p-toluenesulfonyl di-n-butyl amide, N,N'-diethyl-N,N-diphenyl urea, N,N-di-n-butyl urea, etc., aswell as other crystalloidal materials disclosed'in the Jelley and Vittunr U. S. Patent 2,322,027

and in the Manues and Godowsky U. S. Patents 2,304,939 and 2,304,940, as well as the alkyl amides disclosed in the Sawdey and Vittum U. S. Patent 2,533,514.

Emulsion layers containing such dispersions of the couplers are useful in both reversal and negative-positive color development processes of the well known types.

The remaining coupler compounds specified above, couplers Nos. 1, 2, 4, 5, 6, 9, l0 and 11, for example, which are somewhat more difiusible in emulsion layers in the presence of aqueous processing solutions can, however, be used alone or together with other couplers in emulsion layers for various purposes.

The last-mentioned couplers which are more soluble in aqueous alkaline color developing solutions are representative of couplers of the invention which are particularly adapted to use in color developing solutions used for the development of exposed silver halide emulsion layers devoid of coupler compounds such as those employed in well known reversal color development processes.

When the coupler compounds of the invention are employed in emulsion layers of multilayer color films, the couplers can be employed in the red-sensitive cyan image-forming emulsion in the required amount. Accordingly, when the more soluble coupler compounds indicated are employed in the color developing solution, the developing solution can be used for the development of the red-sensitive cyan emulsion layer in the case of a multi-layer color film sensitized in the natural order.

A developer composition suitable for use in the development of exposed silver halide emulsion layers in either reversal or negative-positve color processes is provided as follows:

A. p-Amino-diethylaniline sulfate grams 2 Sodium sulfite (anhydrous) do 5 Sodium carbonate (anhydrous) do 20 Potassium bromide do 2 Water to 1 liter.

B. Coupler grams 2 Sodium hydroxide (2% solution) cc For use, 3 is added to A.

The aromatic amino developing agents used with the coupler compounds of our invention include the mono-, diand triaminoaryl compounds and their derivatives formed by substitution in the amino group as well as in the ring such as alkylphenylenediamines and alkyltoluylenediamines. The compounds are usually used in the salt form, such as the hydrochloride or the sulfate, which are more stable than the amines themselves. Suitable compounds are diethyl-p-phenylenediamine hydrochloride, monoethyl-p-phenylenediamine hydrochloride, dimethylp-phenylenediamine sulfate. Developing agents containing heterocyclic systems as described in U. S. .Patent 2,196,739 are also suitable. The p-aminophenols and their substitution products may also be used where the amino group is unsubstituted. All of these compounds have an unsubstituted amino group which enables the oxidation products of the developer to couple with the color-forming compounds to form a dye image.

Our development process may be employed for the production of colored photographic images in hydrophilic layers of gelatin or other carrier for the silver halide such as collodion, organic esters of cellulose. or synthetic resins. The support for the emulsion may be a transparent material such as glass, cellulose ester or a non-transparent reflecting material such as paper or an opaque cellulose ester. The emulsion may be coated as a single layer on the support or as a superposed layer on one or both sides of the support. 7

What we claim is:

l. The method of producing a colored photographic image in an exposed silver halide emulsion layer which comprises developing the exposed emulsion layer with a primary aromatic amino silver halide developing agent in the presence of a coupler compound selected from the class consisting of compounds having the following general formulas:

COORi and CONHRz wherein R represents a member of the class consisting of amino and acylamido groups, R1 represents a member of the class consisting of an alkyl group of from 1 to 20 carbon atoms and a monocyclic aryl group of the hen- 2,728,660 5 6 zene series, and R2 represents a member of theclass con- References Cited in the file of this patent sisting of a hydrogen atom, an alkyl group of from 1 UNITED STATES PATENTS to 20 carbon atoms, and a rronocyclic aryl group of the benzene series 2,357,394 Frohlich et a1 Sept. 5, 1944 2. A photographic silver halide emulsion layer con- 5 $369,929 vlttufn et 1945 taining a coupler compound designated in claim 1. A2373) Salmmen et July 81 1947 

1. THE METHOD OF PRODUCING A COLORED PHOTOGRAPHIC IMAGE IN AN EXPOSED SILVER HALIDE EMULSION LAYER WHICH COMPRISES DEVELOPING THE EXPOSED EMULSION LAYER WITH A PRIMARY AROMATIC AMINO SILVER HALIDE DEVELOPING AGENT IN THE PRESENCE OF A COUPLER COMPOUND SELECTED FROM THE CLASS CONSISTING OF COMPOUNDS HAVING THE FOLLOWING GENERAL FORMULAS: 